Remote control means



Oct. 31, 1939. VOGT r AL 2,177,850

REMOTE CONTROL MEANS Filed June 4, 1958 2 Sheets-Sheet l ENTORS M f MM/L/ A'T roRNEYs Oct. 31, 1939. G. voe'a' ET AL REMOTE CONTROL MEANS Filed June 4, 1938 2 Sheets-Sheet 2 INVENTORS Lllxlllll-AAAAl-llllll BY HANS ST/ .Q/IOF w fg Wm a/L/ TIORNEYS l i i i w Patented Oct; 31, 1939- UNITED STATES,

PATENT OFFICE REMOTE CONTROL MEANS Gottfried Vogt, Berlin-Tempelhof, and Hans Stierhof, Berlin-Charlottenburg, Germany, as-

signors to Telefunken Gesellschaft fiir Drahtlose Telegraphic m. b. H., Berlin, Germany, a

corporation of Germany Application June 4, 1938, Serial No. 211,848

In Germany June 5, 1937 4 Claims.

at the controlled point is not yet located at the corresponding point of its voltage divider a voltage will arise at the relay which will cause the motor to be cut in circuit. But when the wiper coupled with the device to be adjusted and shifted by the action of the motor at the controlled place roughly has reached the desired position, the potential at the relay will drop to a point where the relay releases and the motor current is cut off, with the result that also the device to be set stays in the position it happens to occupy at the time.

However, an organization of this nature permits of only a rough setting. The reason of such imprecision of setting is that the relay does not release only when the wiper at the controlled place has reached the position where the relay potential is exactly equal to zero, but already a little sooner when the minimum voltage which will still hold the relay (holding or retaining value) is not reached. And this minimum potential is mostly not exactly reproducible.

A modified form of construction is also known in the art in which each of the two voltage dividers is furnished with a bank of fixed taps, and each of these taps, in turn, is connected with a row of stationary contacts. At the controlling place and at the controlled end a like number of fixed taps with the same resistance relation are 40 provided. Each of the two wipers shifts on its corresponding bank or row of contacts which are correspondingly similarly spaced. Since in this arrangement. the fixed contacts are very broad, and since also the breadth of the slide contact or slider is so great that the slide contact is always in physical contact with at least one of the fixed contacts, though frequently with two such fixed contacts, it follows that no exact adjustment will be possible with this arrangement.

Now, according to this invention a higher degree of precision is obtained by making the width of the slider at the controlled place less than the smallest distance of the contacts which are 55 disposed in accordance with the pre-determined corresponding voltage divider then, if the wiper' positions of the device and that corresponding taps on both voltage dividers divide these in the same resistance ratio, independently of the geometric disposition of the contacts; moreover a holding potential is impressed on the relay 5 through a resistance which is high in contrast with the resistances of the voltage dividers.

The advantage of the invention is that the position of the sliding contact or slider at the controlled end at which release happens in the relay isexactly and reproducibly fixed by the position in which the slider happens to make conductive contact with the desired fixed contact. As a consequence the potential at the relay which in all positions of the sliding contact between two neighboring fixed contacts is always the same and which naturally is higher than the voltage required for holding is suddenly short-circuited.

In other words, contradistinct to what is true of the arrangement hereinbefore mentioned from the prior art, the relay voltage does not fall continuously to the zero level, but this happens intermittently, and thus the limiting position is clearly fixed. As a matter of fact, a whole series of pre-arranged positions in the adjustable arrangement can be set with high precision.

Certain exemplified embodiments of the invention are shown in the drawings wherein Fig.

1 illustrates in diagrammatic form a simplified circuit arrangement incorporating the invention using push-buttons; Fig. 2 illustrates an embodiment of the invention utilizing alternating current and wiping contacts; and, Fig. 3 illustratesa type of wiping contact device constructed. in accordance with the present invention.

Referring to the drawings Fig. l, S denotes the control device which may be mounted any desired distance apart from the receiver set proper. E denotes the control device to be d sposed in the receiver set. A and B are voltage dividers provided at the controlling place and at the controlled place, the terminals of which are united with the source of D., C. supply Q.

Both voltage dividers or potentiometers have taps I, 2, 3 and l, 2', 3, which are brought to corresponding terminals a, b, c of a push button assembly s and a, b, c of a multi-polnt switch S respectively. ,Switch S is provided with a wiper K. The push button assembly and the sliding contact mounted on the wiper are united by the control or pilot line L which includes the relay R. As current flows therethrough the said. relay closes the switch 1' and thereby makes the circuit for the setting motor M, the shaft of which,

on the one hand, is connected through a gearing 66 and the motor M set in motion in adefinite di- In parallel relation to the winding N of relay R is connected the series arrangement comprising a D. C. source of voltage supply H and a resistance t whose valueis high in contrast with the resistances of the voltage dividers A and B.

The operation of this arrangement is as follows: If the push-button happens to be depressed on contact b and the slider K' is in contact with the contact a, then there is impressed upon the coil N the voltage difference between'points 2 and l; the result is that the switch 1' is actuated rection. By the coupling also the rotary condenser C will be set and the wiper K rotated. Now, as soon as the slider K is no longer in touch with contact a, releasing of relay and arresting of motor are prevented owing to the fact that to the relay coil through resistance 1. is applied the source H which will then cause a constant current to fiow through the relay coil. It

is only at the instant when the wiper K engages replaced by using the ground. Fig. 2 shows another exemplified embodimentof the invention in which arrangements have been made so that the rotary condenser is always caused' to assume the desired position by traveling the shortest possible way. In this arrangement the. two voltage dividers A and B have their end terminals united with the A.- C. mains U, V. Their taps l to I and l' tol' are brought to the corresponding terminals a to g and a to g, respectively, of multi-point switches S, S, respectively, with wipers K and K. Included in the control 'or pilot line L between the sliders is the polarized relay R. The energization of the relay is eflected by way of the coil T connected with the mains or supply line U, V. The solenoid N is directly contained in the pilot line L. United with the relay R are the retaining or holder contacts 0, 0', and the control contacts 9, 9'. While the holder contacts 0, 0', are connected with the line U, V, the control contacts I D are brought to the terminals of a motor M with reversible sense of rotation.

What may be used for the purpose is a motor of any desired system. The keeper P of relay T actuated by solenoid N is united with a twopole switch 1' whose blades 8 and 8' shift between the holding contacts 0, 0, and the control contacts p, 1) respectively. The blade s is united with phase U of the mains, while blade 8' is connected through a series resistance t and t connected through a series resistance t and t with the beginning and the'end, respectively, of the solenoid N. The motor has a wheel gear 14 with which a clutch V is connected, with the drive shaft to of which is connected the wiper K to the switch S, and further the rotary condensers C serving to change the wavelength of the radio apparatus.

The operation of the distant control selector is as follows:

If the wiper K of the selector W happens to be positioned on one of the contacts 0-9, and the .then, for example, the wiper K is shifted away from contact b to contact 0 a difference of potential will be set up across the ends of line L, with the result that the coil N is energized.

As a result the keeper P the relay is moved outwardly whereby the switch blades 3, s' are united with the contacts 0 and p. The closing of the control or piloting contact 11 has the result that I the motor M is united with the phases U, V, of

the supply mains, and is thus caused to revolve in a certain direction. The wiper K of the switch 8 moves away from the contact b in the direction towards the contact 0'. Owing to the shift of wiper K' from the contact 17', the difference of potential across the ends of the line L is removed. Then, however, the effect of the retaining or holding means makes itself felt, in other words, the current flowingfrom pole V through contact 0, resistances, t, t, solenoid N to pole U of selector W holds the switch 1" in the position it occupied previously. When the wiper K reaches the contact 0', then the current flowing through the coil N is so weakened, or cut down to the zero level, that the switch will be returned into its original position, that is to say, that shown in the drawings.

If wiper K of the switch 8 is shifted from contact L to contact a there will be brought about analogously a shift of the wiper K from contact 11' to the contact a. A given shift of the wiper K or K, respectively, however, means the tuning of the receiver apparatus to another wave-length, that is, to another broadcast station.

For exact setting or re-adjustment to a deflnite wave-length the contact points a to a may be spaced (staggered) a Selector W could also be of the type as shown in Fig. 1, so that, whenever a push button is operated, the adjacent station designation is rendered visible and conspicuous by illumination.

In the arrangement so far disclosed there will still exist a difference-in the adjustments to a definite station that is desired according to whether the latter is approached one way or the' other. The amount of this difference is a function of the width of the fixed contacts and the movable slider. It is recommendable to make the contacts as narrow as possible. But simple means may be suggested so as to make adjustment independent of the direction of tuning adjustment even with finite contact width. This is accomplishable by making the wiper freely movable between two conveniently chosen stops being in turn in rigid connection with the means to be set, rather than coupling the same rigidly with the device to be adjusted. An organization of this kind is shown in Fig. 3. Referring to the same, S denotes a slide or carriage which is attached to the cord R connected with the shaft C of the rotary condenser or condensers by way of pulleys or rollers and which is guided by the strip F. The-said carriage or slide S supports a tactile lever H loosely revoluble in bearing L between two stops Al and A 2. The'said lever cooperates with contacts K mounted upon a straight strip T, and each of the said contacts corresponds push-buttom' to a certain station. Upon movement toward the left-hand side, the said tactile lever is engaged with the right-hand stop; upon movement to the right, it is at the left stop. By suitable adjustment of the stops Al and A2 on the slide, conditions can be made so that contacting between lever and contact is independent of the sense of adjustment.

The bottom end of the lever suitably is supported yieldingly in such a way that on passing over a contact whenever the latter did not yet correspond to the contact to which adjustment had been made at the controlling end, the lever will deflect, though will subsequently be restored to its straight position.

The connection between the tactile lever and the control line is insured most suitably by way of metallic stops Al and A2. Closing of the control line in such case takes place safely only when the lever H actually makes contact, on the one hand, with the desired contact and, on the other hand, with the stop.

We claim:

1. In radio receiving apparatus including motor tuning means, means for remotely controlling said motor comprising an electrical network including a pair of conductors between which a voltage is maintained, a relay ior controlling the operation of said tuning motor, a potentiometer ,connected across said two conductors, said potentiometer being provided with a number of taps arranged thereon at points corresponding to the stations desired to be tuned to from a remote point, a wiping contact device operatively connected to said motor and adapted to be operated by said motor along said taps, a substantially similar potentiometer at the remote point connected across said conductors and provided with similarly arranged taps, a common terminal at said remote point, current conducting means including said motor relay for connecting said common terminal to the wiper, a high resistance and asource of current in series connected across said relay and means at the remote point for connecting said common terminal to any one of the taps thereat.

2. In radio receiving apparatus including motor tuning means, means for remotely controlling said motor and thereby provide remote tuning of the receiver comprising a pair of conductors, between which a voltage is maintained, extending from the remote point to the point at which the receiving apparatus is located, a relay for controlling the operation of the tuning motor, a potentiometer connected across said two conductors, said potentiometer being provided with a number of taps adapted to be positioned along the potentiometer at points corresponding to the various stations to which it is desired to tune from the remote point, a wiping contact device in cooperative relationship with said taps and operatively connected with said motor so as to be operated thereby along said taps, a potentiometer connected across said conductors at the remote point, said last named potentiometer being provided with a number of taps arranged thereon at points corresponding to the stations to which the receiving apparatus is to be selectively tuned to, a common terminal at said remote point, selectively operable means connected between the common terminal and said taps for selectively connecting any one of said taps to said common point, means including said motor controlling relay for connecting said common point to the wiping contact device, and an independent energizing circuit for said motor control relay, said last named circuit being effective only when said wiping contact is not in contact wtih any of said taps.

3. An arrangement as disclosed in the next preceding claim characterized by that an alternating current voltage is maintained between said pair of conductors and by that the motor control relay comprises a polarized relay device provided with reversing contacts arranged to reverse the direction of rotation of the motor, holding contacts associated with said relay for maintaining the relay in operation when the wiping contact is not in contact with any of saidtaps, saidholding contacts being adapted toreverse the holding potential on the relay in the same sense as the' reversing contacts.

4. An arrangement as recited in claim 1 characterized by that the wiping contact device is arranged so as to be capable of tree motion between two stops fixedly connected with the motor.

GOTTFRIED VOGT. HANS BTIERHOI". 

